Power Electronics Engineer, Thermofluids

# About Fluidstack We exist to make humanity more free. For most of human history, you farmed or you starved. Technology gave people more time for the things they wanted to do, instead of things they had to do. Powerful AI will be the biggest lever for human choice we've ever built - but only if models are aligned with what humanity actually wants. There are groups building AI who don't share these goals. Whoever deploys frontier compute infrastructure fastest will decide whether AI expands human freedom or shrinks it. We're singularly focused on delivering 10 to 100s of GWs of compute faster than anyone else, rethinking every layer of the stack. We acquire power, design and build data centers, and operate them - with teams spanning hardware and software. Speed and scale are our key differentiators. Come be a part of building civilization-scale infrastructure for AI. **We hire people who care deeply about this problem space. If that is you, please apply!** # How We Operate - **Be a barrel.** Full autonomy. Own things end to end, take on scope without being asked, no permission required to operate outside your core role. - **Insane urgency.** We drive everything forward as fast as possible. - **Reason from first principles.** Challenge every assumption. Zero analogy thinking, no egos, the best idea wins. - **Love of the game.** The frontier of AI is the most interesting problem of our time. We put in long hours at high intensity to push the frontier forward. - **Build something that actually matters.** If you're going to spend your time, spend it on something that matters to the world. ## **The Thermofluids R&D Team** **Examples of key problems the team is working on** - **Reject 10s of GW of heat, starting now.** Fluidstack is targeting 10s of GW of compute over the next two years. Every watt of it becomes heat that has to go somewhere, and no cooling team has ever been asked to open at that scale rather than grow into it. - **Design and build the machines, because nobody can supply them.** The merchant compressor market cannot deliver at this rate, and the vendor base behind today’s chillers will not scale to gigawatts. We are taking compressor and chiller design in house, working on machine architectures nobody sells today, and going from blank sheet to production faster than this industry thinks is possible. - **Own every thermofluids problem behind the fleet, not just the chiller.** Working fluid and cycle architecture, heat exchangers at a scale that dominates the cost of the plant, two-phase heat transfer at the chip, and thermal energy storage. All of it is open, and whatever this team lands gets built thousands of times. ## **Role Scope** - Own the electrical design of the machine’s power path: the DC bus, the inverter, the motor drive, and the amplifiers driving the magnetic bearings around the rotor. - Specify and integrate the drive for a high-speed hermetic motor, including the switching, thermal, bearing-current and insulation questions that follow from running a machine fast. - Design the power and protection scheme for the test benches and the load bank, so a machine can be run to full rating and its output absorbed or regenerated. - Take the electrical scope through EMC, harmonics and arc flash to an installation that is safe to work on and safe to sign off. - Own electrical safety in the test cell, including the procedures the technicians and test engineers work to around live buses and stored energy. ## **What We're Looking For** **The below is a starting point. We always make space for exceptional people, so if you don't fit this role exactly,** [**tell us where you would**](https://jobs.ashbyhq.com/fluidstack/05c2e69c-42f9-4fcb-9cf0-a467aaf98f1c)**.** - You’ve designed a high-power converter or motor drive that got built, and you were there the first time it drove a real load. - You’ve integrated a drive with a motor somebody else designed, and dealt with what the drive then did to the machine and to everything sharing the bus. - You’ve chased an EMC, harmonic or bearing-current problem to its actual cause instead of adding a filter and hoping. - You’ve written electrical safe work practices and then enforced them on people who found them inconvenient. - You’ve powered up a test cell or a first-of-a-kind installation, and you were the one who decided it was safe to close the breaker. - **Bonus:** High-speed and magnetic-bearing drive systems. Electric propulsion and aerospace power systems (eVTOL, satellite EPS, electric pump-fed engines). 800 V class DC architectures and wide-bandgap devices (SiC, GaN). Test cell power and safe practice around energized work (test benches, load banks, regenerative drives). We are committed to pay equity and transparency. Fluidstack is an Equal Employment Opportunity Employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, national origin, sexual orientation, gender identity, disability and protected veterans’ status, or any other characteristic protected by law. Fluidstack will consider for employment qualified applicants with arrest and conviction records pursuant to applicable law. *You will receive a confirmation email once your application has successfully been accepted. If there is an error with your submission and you **did not** receive a confirmation email, please email with your resume/CV, the role you've applied for, and the date you submitted your application-- someone from our recruiting team will be in touch.*